Identification of PSMD7 as a prognostic factor correlated with immune infiltration in head and neck squamous cell carcinoma

Deubiquitinase PSMD7 facilitates pancreatic cancer progression through activating Nocth1 pathway via modifying SOX2 degradation

BACKGROUND

Ubiquitination is a critical post-translational modification which can be reversed with an enzyme family known as deubiquitinating enzymes (DUBs). It has been reported that dysregulation of deubiquitination leads to carcinogenesis. As a member of the DUBs family, proteasome 26 S subunit non-ATPase 7 (PSMD7) serves as an underlying tumour-promoting factor in multiple cancers. However, the clinical significance and biological functions of PSMD7 in pancreatic cancer (PC) remain unclear.

RESULTS

In this study, we first reported frequent overexpression of PSMD7 in PC tissues, and high levels of PSMD7 were markedly linked to shorter survival and a malignant phenotype in PC patients. An array of in vitro and in vivo gain/loss-of-function tests revealed that PSMD7 facilitates the progression of PC cells. Additionally, we found that PSMD7 promotes PC cell progression by activating the Notch homolog 1 (Notch1) signalling. Interestingly, in PC cells, the inhibitory effect of PSMD7 knockdown on cellular processes was comparable to that observed upon Notch1 knockdown. Mechanistically, PSMD7 deubiquitinated and stabilised sex determining region Y (SRY)-box 2 (SOX2), a key mediator of Notch1 signalling. The stabilisation of SOX2, mediated by PSMD7, dramatically increased SOX2 protein levels, subsequently activating the Notch1 pathway. Finally, restoration of SOX2 expression abrogated the PSMD7-silenced antitumour effect.

CONCLUSIONS

Taken together, our work identifies and validates PSMD7 as a promoter of PC progression through augmentation of the Notch1 signalling pathway mediated by SOX2. This finding suggests that PSMD7 holds promise as a potential therapeutic target for the management of this refractory disease.

Comprehensive analysis of PSMD family members and validation of PSMD9 as a potential therapeutic target in human glioblastoma

AIMS

PSMD family members, as important components of the 26S proteasome, are well known to be involved in protein degradation. However, their role in glioblastoma (GBM) has not been rigorously investigated. We aimed to perform systematic analysis of the expression signature, prognostic significance and functions of PSMD family genes in GBM to reveal potential prognostic markers and new therapeutic targets among PSMD family members.

METHODS

In this study, we systemically analyzed PSMD family members in terms of their expression profiles, prognostic implications, DNA methylation levels, and genetic alterations; the relationships between their expression levels and immune infiltration and drug sensitivity; and their potential functional enrichment in GBM through bioinformatics assessment. Moreover, in vitro and in vivo experiments were used to validate the biological functions of PSMD9 and its targeted therapeutic effect in GBM.

RESULTS

The mRNA levels of PSMD5/8/9/10/11/13/14 were higher in GBM than in normal brain tissues, and the mRNA levels of PSMD1/4/5/8/9/11/12 were higher in high-grade glioma (WHO grade III & IV) than in low-grade glioma (WHO grade II). High mRNA expression of PSMD2/6/8/9/12/13/14 and low mRNA expression of PSMD7 were associated with poor overall survival (OS). Multivariate Cox regression analysis identified PSMD2/5/6/8/9/10/11/12 as independent prognostic factors for OS prediction. In addition, the protein-protein interaction network and gene set enrichment analysis results suggested that PSMD family members and their interacting molecules were involved in the regulation of the cell cycle, cell invasion and migration, and other biological processes in GBM. In addition, knockdown of PSMD9 inhibited cell proliferation, invasion and migration and induced G2/M cell cycle arrest in LN229 and A172 GBM cells. Moreover, PSMD9 promoted the malignant progression of GBM in vivo. GBM cell lines with high PSMD9 expression were more resistant to panobinostat, a potent deacetylase inhibitor, than those with low PSMD9 expression. In vitro and in vivo experiments further validated that PSMD9 overexpression rescued the GBM inhibitory effect of panobinostat.

CONCLUSION

This study provides new insights into the value of the PSMD family in human GBM diagnosis and prognosis evaluation, and we further identified PSMD9 as a potential therapeutic target. These findings may lead to the development of effective therapeutic strategies for GBM.

Deubiquitinating enzyme PSMD7 promotes bladder cancer development: Involvement of RAB1A stabilization

BACKGROUND

Proteasome 26S subunit, non-ATPase 7 (PSMD7) is a deubiquitinating enzyme that is involved in the stability of ubiquitinated proteins and participates in the development of multiple types of cancer. The roles of PSMD7 and its potential mechanisms in bladder cancer (BC) remain elusive.

METHODS

In this study, we identified that PSMD7 was overexpressed in BC tissues based on gene expression omnibus (GEO) database and TNMplot web. To investigate the functional role of PSMD7, two BC cell lines, T24 and 5637, were selected. The cells were transfected with vectors containing short hairpin RNAs against PSMD7 or plasmids containing full-length PSMD7 to knockdown or overexpress PSMD7.

RESULTS

Our results revealed that silencing PSMD7 inhibited cell proliferation, cycle progression, migration, invasion, and promoted cell apoptosis, whereas PSMD7 overexpression led to the opposite effects in the BC cells. Mechanically, PSMD7 influenced the protein expression but not the mRNA expression of the Ras-related protein Rab-1 A (RAB1A). PSMD7 combined with RAB1A and negatively regulated its ubiquitination, indicating that PSMD7 enhanced the stability of RAB1A through post-transcriptional modification. Moreover, the rescue experiment demonstrated that RAB1A was an important downstream effector molecule of PSMD7. Besides, the negative regulation of silencing PSMD7 on tumor growth was confirmed in mice.

CONCLUSIONS

Our study substantiated a novel mechanism by which PSMD7 stabilized RAB1A to accelerate the progression of BC.

The potential bioactive ingredients and hub genes of five TCM prescriptions against lung adenocarcinoma were explored based on bioinformatics

Analysis of the commonness of several prescriptions of traditional Chinese medicine (TCM) in the treatment of lung adenocarcinoma (LUAD) based on bioinformatics. Searched the TCM prescriptions for the treatment of LUAD in the literature published in the database, searched ingredients in the TCM through TCMSP and Swiss target prediction databases (OB ≥ 30%, DL > 0.18, Caco-2 > 0), and predicted the potential targets. GEO database retrieved LUAD gene chip data and screened (P < 0.05, | log2 (fold change) |> 1). The biological function, hub gene selection and survival period, immune infiltration, methylation, copy number variations (CNVs), and single-nucleotide variants (SNV) of hub genes were analyzed by DAVID, STRING, Kaplan-Meier plotter database, Cytoscape software, GSCALite database, and TIMER2.0. In this study, 5 TCM prescriptions were analyzed, and a total of 173 ingredients were obtained through database search, including 35 coincidence ingredients, a total of 603 potential targets, 621 LUAD-related genes, 16 up-regulated genes, and 31 down-regulated genes. A total of 61 terms of biological process (BP), 14 terms of cellular component (CC), and 14 terms of molecular function (MF) were obtained. Twenty core genes were obtained, including 15 genes with different survival periods, which were closely related to immune cells (B cell, CD8 + T cell, CD4 + T cell, macrophage, neutrophil, and dendritic cells). The low expression of ADRB2 and MAOA and the high expression of AUARK, CDK1, KIF11, MIF, TOP2A, and TTK were associated with the survival rate of LUAD patients (P < 0.05). Baicalein, Arachidonate, Hederagenin, and hub genes may become potential drugs and potential targets for LUAD treatment. Evaluated the efficacy of TCM in the treatment of LUAD from macro to micro, mined the hub genes, and predicted the mechanism of action, so as to lay the foundation for the development of new drugs of TCM, prescription optimization, or disease control.

PSMD8 can serve as potential biomarker and therapeutic target of the PSMD family in ovarian cancer: based on bioinformatics analysis and in vitro validation

BACKGROUND

The ubiquity-proteasome system is an indispensable mechanism for regulating intracellular protein degradation, thereby affecting human antigen processing, signal transduction, and cell cycle regulation. We used bioinformatics database to predict the expression and related roles of all members of the PSMD family in ovarian cancer. Our findings may provide a theoretical basis for early diagnosis, prognostic assessment, and targeted therapy of ovarian cancer.

METHODS

GEPIA, cBioPortal, and Kaplan-Meier Plotter databases were used to analyze the mRNA expression levels, gene variation, and prognostic value of PSMD family members in ovarian cancer. PSMD8 was identified as the member with the best prognostic value. The TISIDB database was used to analyze the correlation between PSMD8 and immunity, and the role of PSMD8 in ovarian cancer tissue was verified by immunohistochemical experiments. The relationship of PSMD8 expression with clinicopathological parameters and survival outcomes of ovarian cancer patients was analyzed. The effects of PSMD8 on malignant biological behaviors of invasion, migration, and proliferation of ovarian cancer cells were studied by in vitro experiments.

RESULTS

The expression levels of PSMD8/14 mRNA in ovarian cancer tissues were significantly higher than those in normal ovarian tissues, and the expression levels of PSMD2/3/4/5/8/11/12/14 mRNA were associated with prognosis. Up-regulation of PSMD4/8/14 mRNA expression was associated with poor OS, and the up-regulation of PSMD2/3/5/8 mRNA expression was associated with poor PFS in patients with ovarian serous carcinomas. Gene function and enrichment analysis showed that PSMD8 is mainly involved in biological processes such as energy metabolism, DNA replication, and protein synthesis. Immunohistochemical experiments showed that PSMD8 was mainly expressed in the cytoplasm and the expression level was correlated with FIGO stage. Patients with high PSMD8 expression had poor prognosis. Overexpression of PSMD8 significantly enhanced the proliferation, migration, and invasion abilities in ovarian cancer cells.

CONCLUSION

We observed different degrees of abnormal expression of members of PSMD family in ovarian cancer. Among these, PSMD8 was significantly overexpressed in ovarian malignant tissue, and was associated with poor prognosis. PSMDs, especially PSMD8, can serve as potential diagnostic and prognostic biomarkers and therapeutic targets in ovarian cancer.

The Role of Deubiquitinating Enzyme in Head and Neck Squamous Cell Carcinoma

Ubiquitination and deubiquitination are two popular ways for the post-translational modification of proteins. These two modifications affect intracellular localization, stability, and function of target proteins. The process of deubiquitination is involved in histone modification, cell cycle regulation, cell differentiation, apoptosis, endocytosis, autophagy, and DNA repair after damage. Moreover, it is involved in the processes of carcinogenesis and cancer development. In this review, we discuss these issues in understanding deubiquitinating enzyme (DUB) function in head and neck squamous cell carcinoma (HNSCC), and their potential therapeutic strategies for HNSCC patients are also discussed.

19S Proteasome Subunits as Oncogenes and Prognostic Biomarkers in FLT3-Mutated Acute Myeloid Leukemia (AML)

26S proteasome non-ATPase subunits 1 (PSMD1) and 3 (PSMD3) were recently identified as prognostic biomarkers and potential therapeutic targets in chronic myeloid leukemia (CML) and multiple solid tumors. In the present study, we analyzed the expression of 19S proteasome subunits in acute myeloid leukemia (AML) patients with mutations in the FMS-like tyrosine kinase 3 (FLT3) gene and assessed their impact on overall survival (OS). High levels of PSMD3 but not PSMD1 expression correlated with a worse OS in FLT3-mutated AML. Consistent with an oncogenic role for PSMD3 in AML, shRNA-mediated PSMD3 knockdown impaired colony formation of FLT3+ AML cell lines, which correlated with increased OS in xenograft models. While PSMD3 regulated nuclear factor-kappa B (NF-κB) transcriptional activity in CML, we did not observe similar effects in FLT3+ AML cells. Rather, proteomics analyses suggested a role for PSMD3 in neutrophil degranulation and energy metabolism. Finally, we identified additional PSMD subunits that are upregulated in AML patients with mutated versus wild-type FLT3, which correlated with worse outcomes. These findings suggest that different components of the 19S regulatory complex of the 26S proteasome can have indications for OS and may serve as prognostic biomarkers in AML and other types of cancers.

Proteomics Analysis of Aqueous Humor and Rejected Graft in Pig-to-Non-Human Primate Corneal Xenotransplantation

Although pig-to-non-human primate (NHP) corneal xenotransplantation has shown long-term graft survival, xenogeneic antigen-related immune responses are still stronger than allogeneic antigen-associated responses. Therefore, there is an unmet need to investigate major rejection pathways in corneal xenotransplantation, even with immunosuppression. This study aimed to identify biomarkers in aqueous humor for predicting rejection and to investigate rejection-related pathways in grafts from NHPs transplanted with porcine corneas following the administration of steroids combined with tacrolimus/rituximab. NHPs who had received corneas from wild-type (WT) or α-1,3-galactosyltransferase gene-knockout (GTKO) pigs were divided into groups with or without rejection according to clinical examinations. Liquid chromatography-mass spectrometry (LC-MS) was used to analyze the proteomes of corneal tissues or aqueous humor. The biological functions of differentially expressed proteins (DEPs) were assessed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for pathways and protein–protein interaction network analysis. Among the 66 DEPs in aqueous humor, complement proteins (C3, C5, and C9) and cholesterol metabolic proteins (APOA1 and APOA2) were related to xenogeneic rejection as biomarkers, and alternative pathways of the complement system seemed to be important in xenogeneic graft rejection. Among the 416 DEPs of the cornea, NF-κB1 and proteosomes (PSMD7, PSMA5, and PSMD3) seemed to be related to xenogeneic graft rejection. Additionally, oxidative phosphorylation and leukocyte activation-related pathways are involved in rejection. Overall, our proteomic approach highlights the important role of NF-κB1, proteosomes, oxidative phosphorylation, and leukocyte activation-related inflammation in the cornea and the relevance of complement pathways of the aqueous humor as a predictive biomarker of xenogeneic rejection.

Deubiquitinase PSMD7 promotes the proliferation, invasion, and cisplatin resistance of gastric cancer cells by stabilizing RAD23B

Ubiquitination, a crucial post-translational modification, controls substrate degradation and can be reversed by deubiquitinases (DUBs). An increasing number of studies are showing that DUBs regulate the malignant behavior and chemotherapy resistance of gastric cancer (GC) by stabilizing various proteins. However, the expression level and biological function of the DUB, proteasome 26S subunit, non-ATPase 7 (PSMD7), in GC remains unknown. Herein, we report for the first time that PSMD7 is frequently overexpressed in GC tissues. Elevated levels of PSMD7 were also detected in GC cell lines. Notably, the upregulation of PSMD7 closely correlated with malignant clinical parameters and reduced the survival of GC patients. Functionally, we found that PSMD7 knockdown consistently suppressed the proliferation, migration, and invasion of AGS and SGC-7901 cells. Ectopic expression of PSMD7 facilitated GC cell proliferation and mobility. Based on protein-protein interaction prediction, RAD23 homolog B (RAD23B) protein was identified as a candidate substrate of PSMD7. PSMD7 positively regulated the abundance of RAD23B and xeroderma pigmentosum, complementation group C (XPC) protein in GC cells. The interaction between PSMD7 and RAD23B was confirmed using protein immunoprecipitation. PSMD7 knockdown enhanced the ubiquitination and degradation of RAD23B protein in GC cells. PSMD7 promoted cell viability, apoptosis resistance, and DNA damage repair in GC cells upon cisplatin (DDP) treatment. Moreover, PSMD7 silencing inhibited tumor growth and enhanced the sensitivity of GC cells to DDP treatment in mice. In summary, PSMD7 was highly expressed in GC and contributed to the malignant behavior and DDP resistance of tumor cells by stabilizing RAD23B.